Logan Kleinwaks made me aware of a very interesting source, which he
will index in his site genealogy indexer http://genealogyindexer.org/
This source is
The annual records of the "Society for mutual aid of the trade
businesses of mosaic faith of Warsaw", >from 1880 to 1930, digitized by
the University of Warsaw.
I have a question of cultural/sociological nature about this Society:
were all the members "modernized" merchants jews ?
The reason I suspect this is two fold: first I found my grand-father
Berek Rotenstein, not with his jewish given name Ber/Berek but with the
"polish" ( actually french!) given name Bernard, and many ( not all)
members have similar polish given names: Maurycy, Maksym, ...
The other reason is that other well known merchants of Warsaw at that
time were not members of this Society.
Nicole BERLINE, Paris.